For diagnostic, therapeutic and surgical medical interventions, light sources for providing illumination light and/or light for exciting fluorescence, for hardening materials and for other purposes are generally required. By way of example, in the case of endoscopic interventions, the light source is generally arranged on the proximal end of the endoscope or connected to the latter by a flexible optical fiber. In order to be able to transmit as much light power or light flux as possible by means of optical waveguides which are as thin as possible, a light source with radiance L which is as high as possible is required.
In the case of endoscopes, a transmission of light by means of a single optical waveguide (in particular by means of a single bundle of optical fibers) is desired, even in the case of a plurality of different light sources, for example for illumination light (which is as white as possible) and for light for exciting fluorescence. For the purposes of beam combining or for superimposing light from a plurality of light sources, use is made, in particular, of faces reflecting in a dichroic or wavelength-dependent and/or polarization-dependent manner. Examples are described in WO 02080803 A1, DE 10 2007 049 626 A1 and DE 10 2010 027 540 A1. A disadvantage of many conventional arrangements consists of these not being very compact and/or not being sufficiently mechanically robust for preventing, in a sufficiently reliable manner, a misalignment as a result of mechanical impact or other influences occurring during practical use.